Editorial Type:
Article
Article Type:
Research Article

Convective Storm Structures and Ambient Conditions Associated with Severe Weather over the Northeast United States

Kelly A. Lombardo School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York

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Brian A. Colle School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York

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Print Publication:
01 Dec 2011
DOI:
https://doi.org/10.1175/WAF-D-11-00002.1
Page(s):
940–956
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Abstract

This study documents the convective storm structures and ambient conditions associated with severe storms (wind, hail, and tornado) over the northeastern United States for two warm seasons (May–August), including 2007 and a warm season comprising randomly selected days from 2002 to 2006. The storms were classified into three main convective organizational structures (cellular, linear, and nonlinear) as well as several subcategories. The same procedure was applied to the highly populated coastal zone of the northeastern United States, including New Jersey, Connecticut, Rhode Island, and New York. The coastal analysis included six warm seasons from 2002 to 2007. Over the Northeast, severe wind events are evenly distributed among the cellular, linear, and nonlinear structures. Cellular structures are the primary hail producers, while tornadoes develop mainly from cellular and linear structures. Over the coastal zone, primarily cellular and linear systems produce severe wind and hail, while tornadoes are equally likely from all three convective structures. Composites were generated for severe weather days over the coastal region for the three main convective structures. On average, severe cellular events develop during moderate instability [most unstable CAPE (MUCAPE) ~1200 J kg−1], with low-level warm-air advection and frontogenesis at the leading edge of a thermal ridge collocated with an Appalachian lee trough. Severe linear events develop in a similar mean environment as the cellular events, except that most linear events occur with a surface trough upstream over the Ohio River valley and half of the linear events develop just ahead of progressive midlevel troughs. Nonlinear severe events develop with relatively weak mean convective instability (MUCAPE ~460 J kg−1), but they are supported by midlevel quasigeostrophic (QG) forcing for ascent.

Corresponding author address: Dr. Kelly Lombardo, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000. E-mail: kellyann.lombardo@gmail.com

Abstract

This study documents the convective storm structures and ambient conditions associated with severe storms (wind, hail, and tornado) over the northeastern United States for two warm seasons (May–August), including 2007 and a warm season comprising randomly selected days from 2002 to 2006. The storms were classified into three main convective organizational structures (cellular, linear, and nonlinear) as well as several subcategories. The same procedure was applied to the highly populated coastal zone of the northeastern United States, including New Jersey, Connecticut, Rhode Island, and New York. The coastal analysis included six warm seasons from 2002 to 2007. Over the Northeast, severe wind events are evenly distributed among the cellular, linear, and nonlinear structures. Cellular structures are the primary hail producers, while tornadoes develop mainly from cellular and linear structures. Over the coastal zone, primarily cellular and linear systems produce severe wind and hail, while tornadoes are equally likely from all three convective structures. Composites were generated for severe weather days over the coastal region for the three main convective structures. On average, severe cellular events develop during moderate instability [most unstable CAPE (MUCAPE) ~1200 J kg−1], with low-level warm-air advection and frontogenesis at the leading edge of a thermal ridge collocated with an Appalachian lee trough. Severe linear events develop in a similar mean environment as the cellular events, except that most linear events occur with a surface trough upstream over the Ohio River valley and half of the linear events develop just ahead of progressive midlevel troughs. Nonlinear severe events develop with relatively weak mean convective instability (MUCAPE ~460 J kg−1), but they are supported by midlevel quasigeostrophic (QG) forcing for ascent.

Corresponding author address: Dr. Kelly Lombardo, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000. E-mail: kellyann.lombardo@gmail.com
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  • Banacos, P. C., and Ekster M. L. , 2010: The association of the elevated mixed layer with significant severe weather events in the northeastern United States. Wea. Forecasting, 25, 1082–1102.

    • Search Google Scholar
    • Export Citation

  • Bosart, L. F., Seimon A. , LaPenta K. D. , and Dickinson M. J. , 2006: Supercell tornadogenesis over complex terrain: The Great Barrington, Massachusetts, tornado on 29 May 1995. Wea. Forecasting, 21, 897–922.

    • Search Google Scholar
    • Export Citation

  • Brooks, H. E., Doswell C. A. III, and Kay M. P. , 2003: Climatological estimates of local daily tornado probability for the United States. Wea. Forecasting, 18, 626–640.

    • Search Google Scholar
    • Export Citation

  • Carlson, T. N., and Ludlam F. H. , 1968: Conditions for the occurrence of severe local storms. Tellus, 20, 203–226.

  • Clark, A. J., Schaffer C. J. , Gallus W. A. Jr., and Johnson-O’Mara K. , 2009: Climatology of storm reports relative to upper-level jet streaks. Wea. Forecasting, 24, 1032–1051.

    • Search Google Scholar
    • Export Citation

  • Cohen, A. E., Coniglio M. C. , Corfidi S. F. , and Corfidi S. J. , 2007: Discrimination of mesoscale convective system environments using sounding observations. Wea. Forecasting, 22, 1045–1062.

    • Search Google Scholar
    • Export Citation

  • Coniglio, M. C., Stensrud D. J. , and Richman M. B. , 2004: An observational study of derecho-producing convective systems. Wea. Forecasting, 19, 320–337.

    • Search Google Scholar
    • Export Citation

  • Doswell, C. A., III, Brooks H. E. , and Kay M. P. , 2005: Climatological estimates of daily local nontornadic severe thunderstorm probability for the United States. Wea. Forecasting, 20, 577–595.

    • Search Google Scholar
    • Export Citation

  • Duda, J. D., and Gallus W. A. Jr., 2010: Spring and summer midwestern severe weather reports in supercells compared to other morphologies. Wea. Forecasting, 25, 190–206.

    • Search Google Scholar
    • Export Citation

  • Evans, J. S., and Doswell C. A. III, 2001: Examination of derecho environments using proximity soundings. Wea. Forecasting, 16, 329–342.

    • Search Google Scholar
    • Export Citation

  • Farrell, R. J., and Carlson T. N. , 1989: Evidence for the role of the lid and underrunning in an outbreak of tornadic thunderstorms. Mon. Wea. Rev., 117, 857–871.

    • Search Google Scholar
    • Export Citation

  • Gallus, W. A., Jr., Snook N. A. , and Johnson E. V. , 2008: Spring and summer severe weather reports over the Midwest as a function of convective mode: A preliminary study. Wea. Forecasting, 23, 101–113.

    • Search Google Scholar
    • Export Citation

  • Giordano, L. A., and Fritsch J. M. , 1991: Strong tornadoes and flash-flood-producing rainstorms during the warm season in the mid-Atlantic region. Wea. Forecasting, 6, 437–455.

    • Search Google Scholar
    • Export Citation

  • Johns, R. H., 1982: A synoptic climatology of northwest flow severe weather outbreaks. Part I: Nature and significance. Mon. Wea. Rev., 110, 1653–1663.

    • Search Google Scholar
    • Export Citation

  • Johns, R. H., 1984: A synoptic climatology of northwest-flow severe weather outbreaks. Part II: Meteorological parameters and synoptic patterns. Mon. Wea. Rev., 112, 449–464.

    • Search Google Scholar
    • Export Citation

  • Johns, R. H., and Dorr R. A. Jr., 1996: Some meteorological aspects of strong and violent tornado episodes in New England and eastern New York. Natl. Wea. Dig., 20 (4), 2–12.

    • Search Google Scholar
    • Export Citation

  • LaPenta, K. D., Bosart L. F. , Galarneau T. J. Jr., and Dickinson M. J. , 2005: A multiscale examination of the 31 May 1998 Mechanicville, New York, tornado. Wea. Forecasting, 20, 494–516.

    • Search Google Scholar
    • Export Citation

  • Lombardo, K. A., and Colle B. A. , 2010: The spatial and temporal distribution of organized convective structures over the northeast United States and their ambient conditions. Mon. Wea. Rev., 138, 4456–4474.

    • Search Google Scholar
    • Export Citation

  • Maddox, R. A., and Doswell C. A. III, 1982: An examination of jet stream configurations, 500 mb vorticity advection and low-level thermal patterns during extended periods of intense convection. Mon. Wea. Rev., 110, 184–197.

    • Search Google Scholar
    • Export Citation

  • Mesinger, F., and Coauthors, 2006: North American Regional Reanalysis. Bull. Amer. Meteor. Soc., 87, 343–360.

  • Miller, J. E., 1948: On the concept of frontogenesis. J. Atmos. Sci., 5, 169–171.

  • Murray, J. C., and Colle B. A. , 2011: The spatial and temporal variability of convective storms over the northeast United States during the warm season. Mon. Wea. Rev., 139, 992–1012.

    • Search Google Scholar
    • Export Citation

  • Parker, M. D., and Johnson R. H. , 2000: Organizational modes of midlatitude mesoscale convective systems. Mon. Wea. Rev., 128, 3413–3436.

    • Search Google Scholar
    • Export Citation

  • Thompson, R. L., Edwards R. , Hart J. A. , Elmore K. L. , and Markowski P. , 2003: Close proximity soundings within supercell environments obtained from the Rapid Update Cycle. Wea. Forecasting, 18, 1243–1261.

    • Search Google Scholar
    • Export Citation

  • Wasula, A. C., Bosart L. F. , and LaPenta K. D. , 2002: The influence of terrain on the severe weather distribution across interior eastern New York and western New England. Wea. Forecasting, 17, 1277–1289.

    • Search Google Scholar
    • Export Citation

  • Weckwerth, T. M., and Wakimoto R. M. , 1992: The initiation and organization of convective cells atop a cold-air outflow boundary. Mon. Wea. Rev., 120, 2169–2187.

    • Search Google Scholar
    • Export Citation

  • Weisman, M., and Klemp J. , 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504–520.

    • Search Google Scholar
    • Export Citation

  • Zwiers, F. W., 1990: The effect of serial correlation on statistical inferences made with resampling procedures. J. Climate, 12, 1452–1460.

    • Search Google Scholar
    • Export Citation
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